Python 2.3, Python for Series 60 1.4.5 still in use… and insight into Symbian deployment process and user experience

Nokia’s Python for Series 60 has a long history. It is a Python interpreter, originally escaped from Nokia prototype labs, running in your phone. It is said to been awesome to show mobile/embedded developers, who were love with their static C compilers and 4 hours built times, opening a Python prompt in your phone and typing import audio; audio.say(“your phone loves Python”) by keypad (Nokia Series 60 phones come with a speech synthetizer). Python for Series 60 is the best tool of building a simple proof of concept mobile applications. The lack of speed, lack of good UI libraries and difficult deployment problems makes it challenging to use it in production grade environments.

PyS60 has also a history of staying in archaid Python version – namely Python 2.3. It was not until this February when stable PyS60 2.0.0 with Python 2.5 was released (1.9.x was considered experimental according to the release notes). Luckily looks like new winds are blowing (Qt acquisition, Meego/Maemo) and Python is getting higher priority. For example, PySide Qt bindings is very high profile project. Based on this, we hope to expect Python to the first class citizen in the future Meego and Symbian devices.

My company had a little side venture with PyS60 Community Edition when we were still betting that Symbian and Python would rock the world – the era before iPhone changed the game.  PyS60 community edition was effectively a revamped PyS60 1.4.x with Python 2.3 toolchain which actually made PyS60 application production deployment possible. Possible…? -you ask. Madness… no. It is Symbian. It is certification and signing and obscure error messages. Basically vanilla PyS60 is being shipped as an external SIS (Symbian package format) and Symbian platform security makes it impossible to deploy two production signed applications using vanilla PyS60 on the same device. The only cure was statically building Python for both apps from the scratch, which is exactly what PyS60 Community Edition was doing.

But this all was long long time ago. Aeons in mobile time. So I was today surprised when I got email from a person (David) using PyS60 Community Edition. We never upgraded PyS60 Community Edition to Python 2.5 . In fact we haven’t touched the project about two years. David was effectively using Python 2.3 and asked questions about the tool chain internals.

My first answer was a question Why on Earth you are still using Python 2.3? I thought maybe the guy had somehow missed the last two years or was a stuck with an old phone.

However… this was not the case and the answer was very insigtful.

Yes, I’m aware of PyS60 2.0.0, but I prefer PythonCommunity, at least for the moment: no OpenC neither Platform Services dependencies; smaller .SIS size and memory footprint. I think that the final .SIS produced with PythonCommunity, with everything necessary to run contained in it and with a clean installation without multiple dependencies, is a better fit for a mass-market than the files produced by PyS60 2.0.0, above all taking into account that people don’t know what S60 or Symbian are.

Also, the runtime deployment on the new PyS60 isn’t automatic for S60_3rd and S60_FP1 devices, so in the worst case scenario, users may end having to learn to install the different files (pips.sis, ssl.sis, stdioserver.sis, Python_2.0.0.sis, PythonScriptShell_2.0.0.sis) in the correct order, which is a big no-no for a mass-market deployment.

So…. I hope someone in Nokia is reading this blog entry carefully. Do it like Apple does. Make your application deployment static. Make OpenC static. Make every freaking library which is not shipped with the device statically buildable. It should be possible now when everything is open source. It will consume precious device RAM, but at least it will make mass market application development possible. SIS hell is worse hell than deb hell, or DLL hell, as the end user cannot fix it due to device security.

In the related news SIS smart installer was announced few weeks ago. Personally I wouldn’t bet it can deal with all the problems of versioning and Symbian platform security. Forum reports aren’t promising and looks like very Symbianish user experience can be expected. In positive light, it seems that Python is being considered for this process.

Read our blog  Subscribe mFabrik blog in a reader Follow us on Twitter Mikko Ohtamaa on LinkedIn

PyS60 application release build toolchain

A common question for Python for Series 60 newcomers is how to build standalone Symbian applications from Python source code. We have been using Makefile based toolchain internally. I describe it in this picture, I didn’t bother to add thumbnail for the image, since it’s a 3400 pixels wide diagram.

The diagram describes building a PyS60 application with some Python extensions (Symbian native C++) mixed in and bundling it all to one downloadable SIS file. The application will appear as any first class S60 application in the menu and the user does not know it’s running Python internally, besides bad installation experience (it challenges Microsoft installers with all those unnecessary yes/no questions), extra uninstaller entries and slow start-up time.

The biggest problems are caused by embedded SISs (SIS inside other SIS files) which are not treaded very wel by several Symbian parties.  In theory, it could be build one monolithic SIS, but you’d need to recompile PyS60 from scratch and patch UIDs inside it for your own UIDs received from symbiansigned.com. We are planning to explore SCons based build solution to address this problem, since Makefiles are a bit unflexible with tasks like PKG file and UID range generation.

Here is a PKG file example for final user distributable SIS file.

Also, see UIKludges project for additional details for PKG files of Python extensions.

You need to have

• Ensymble tool
• Series 60 SDK (contains some old GNU make)

You need to master

• A build tool (make)
• Symbian PKG file structure
• Lots of different command line tools

Pros

• It’s the best one we have for now

Cons

• Symbian signing and certification companies don’t understand embedded SIS files (all SIS files must be signed prior embedding) and may have hard time signing SIS files containing only an extension DLL for Pyton. Symbian Signed test criteria has been built only UI application based SIS files in the mind.
• You cannot cook your own patched PyS60 distribution without revamping some hardcoded UIDs and paths, since otherwise there are UID conflicts (EXE and DLL file UIDs are in Nokia’s protected range)
• S60 installers askes extra confirmation for every embedded SIS file, even in the middle of the progress bar, so the user experience of installation is screwed up
• There will extra uninstallation entry for every embedded SIS file in S60 application manager confusing the user
• As you can see, most cons come from Symbian and Symbian signing limitations and have nothing to do with Python

Ps. I would have put this thing to wiki.opensource.nokia.com, but their webmaster email address is non-functional and one cannot upload images to their Wiki.